User`s guide

Triggering 4
InfiniiVision Oscilloscopes User’s Guide 121
5 Press the Signals softkey to display the I
2
C Signals Menu.
6 Connect an oscilloscope channel to the SCL (serial clock) line in the device under test,
then set the SCL clock channel softkey to that channel.
As you press the SCL softkey (or rotate the Entry knob), the SCL label for the source
channel is automatically set and the channel you select is shown in the upper-right
corner of the display next to “I
2
C”.
7 Set the trigger levels for the SCL and SDA signals to the middle of the signals:
• If your I
2
C signals are connected to analog channels, press the SCL softkey and
rotate the Trigger Level knob, then press the SDA softkey and rotate the Trigger
Level knob.
• If your I
2
C signals are connected to digital channels (this applies to MSO model
oscilloscopes only), press the [D15-D0] key and the Thresholds softkey to access
the threshold level setting softkeys and set the thresholds to the approximate
middle of the signals.
8 Choose 7-bit or 8-bit address size. Use 8-bit address size to include the R/W bit as part
of the address value, or choose 7-bit address size to exclude the R/W bit from the
address value.
9 Connect an oscilloscope channel to the SDA (serial data) line in the device under test,
then set the SDA data channel softkey to that channel.
10 As you press the SDA softkey (or rotate the Entry knob), the SDA label for the source
channel is automatically set and the channel you select is shown in the upper-right
corner of the display next to “I
2
C”.
Adjust the trigger level for the selected analog channel by turning the Trigger Level
knob. Press the [D15-D0] key and select Thresholds to set the threshold level for
digital channels. The value of the trigger level or digital threshold is displayed in the
upper-right corner of the display.
Data needs to be stable during the whole high clock cycle or it will be interpreted as a
start or stop condition (data transitioning while the clock is high).
SCL Clock
channel
SDA Data
channel
Return to
previous menu